Compressor

ABSTRACT

An oil circulation ratio OCR of a compressor is reduced with a simple structure. A cylinder head  104  has a suction chamber  141  formed on the inside thereof in a radial direction and a discharge chamber  142  formed on the outside thereof in the radial direction, the suction and discharge chambers being separated by a first annular partition wall  104   d . An oil storage chamber  148  is formed at a central portion of the cylinder head  104  by being separated from the suction chamber  141  by a second annular partition wall  104   e . A pressure release passage  146  ( 101   c   →101   d   →103   c   →148→104   e   1 ) allows a crank chamber  140  and the suction chamber  141  to communicate with each other. The oil storage chamber  148  forms a portion of the pressure release passage  146 , separates oil from a refrigerant flowing through the pressure release passage  146 , and stores the oil.

TECHNICAL FIELD

The present invention relates to a compressor that is primarily used for air-conditioning systems for vehicles, and in particular, relates to a technique for reducing the amount of lubricating oil that flows out of a compressor into an external refrigerant circuit.

BACKGROUND ART

A compressor disclosed in Patent Document 1 includes a cylinder block that has a plurality of cylinder bores and has a piston mounted on each of the cylinder bores, and a cylinder head that is disposed on one end side of the cylinder block via a valve plate and defines a suction chamber on the inside thereof in a radial direction and a discharge chamber on the outside thereof in the radial direction. The piston is reciprocated by a swash plate that rotates in synchronization with a driving shaft to draw a refrigerant into the cylinder bore from the suction chamber and compress the refrigerant within the cylinder bore to discharge the refrigerant to the discharge chamber.

In such a compressor, lubricating oil is mixed into a refrigerant gas, and the lubrication of respective parts of the compressor is performed. Here, if the lubricating oil flows out into an external refrigerant circuit, system efficiency decreases. Therefore, reducing the amount of the lubricating oil that flows out of the compressor into the external refrigerant circuit, that is, a reduction in an oil circulation ratio (OCR) has been required.

For this reason, in the compressor disclosed in Patent Document 1, a partition member is provided to partition the suction chamber into a first space to which a suction passage from the outside is connected on a bottom wall side of the cylinder head and a second space on the valve plate side, and this partition member is provided with a communication passage that allows the first space and the second space to communicate with each other. Also, a pressure release passage, which releases the pressure of a crank chamber behind the piston in which the swash plate is disposed, to the suction chamber, is connected to the first space.

According to the above configuration, the lubricating oil that flows out of the crank chamber together with the refrigerant flows into the first space and is stored therein, and the refrigerant gas from which the lubricating oil is separated passes through the second space, and then is compressed and discharged. As a result, it is possible to suppress the outflow of the oil to the external refrigerant circuit.

REFERENCE DOCUMENT LIST Patent Document

Patent Document 1: JP 2014-095301 A

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, the configuration disclosed in Patent Document 1 has the following problems.

(1) Although there are advantages in that the partition member is capable of being integrally formed with the head gasket and an exclusive partition member becomes unnecessary, the shape of the head gasket provided with the partition member is complicated.

(2) Since the second space is between the valve plate and the first space (oil storage chamber), there is a restriction on a path that connects the pressure release passage to the first space (oil storage chamber).

(3) The periphery of the first space (oil storage chamber) is the discharge chamber, and the stored oil is influenced by the transfer of heat from high-temperature discharge gas. Accordingly, the viscosity of the oil decreases and lubrication performance deteriorates.

An object of the present invention is to provide a compressor capable of solving the above problems.

Means for Solving the Problems

A compressor according to the present invention includes, as a premise, a cylinder block that has a plurality of cylinder bores and has a piston mounted at each of the cylinder bores, and a cylinder head that is disposed on one end side of the cylinder block via a valve plate and defines a suction chamber on the inside thereof in a radial direction and a discharge chamber on the outside thereof in the radial direction. The piston is reciprocated by a swash plate that rotates in synchronization with a driving shaft to draw a refrigerant into the cylinder bore from the suction chamber and compress the refrigerant within the cylinder bore to discharge the refrigerant to the discharge chamber.

Also, the compressor according to the present invention is characterized by including a pressure release passage that allows a crank chamber, in which the swash plate is disposed, and the suction chamber to communicate with each other; and an oil storage chamber that forms a portion of the pressure release passage and separates oil from the refrigerant flowing through the pressure release passage to store the oil. The oil storage chamber is defined by an annular partition wall and the valve plate. The annular partition wall is formed integrally with the cylinder head, is provided to protrude toward the valve plate from a bottom wall of the cylinder head, and has an outer peripheral portion surrounded by the suction chamber.

Effects of the Invention

According to the present invention, since the annular partition wall that defines the oil storage chamber is formed integrally with the cylinder head, it is possible to easily form the oil storage chamber.

Additionally, since the oil storage chamber is defined by the valve plate, it is possible to easily connect the pressure release passage to the oil storage chamber.

Additionally, the periphery of the oil storage chamber is the suction chamber, and is separated from the discharge chamber. Therefore, the oil that flows out of the crank chamber into the oil storage chamber and is stored therein is cooled by a drawn in refrigerant. Hence, it is possible to reduce a decrease in the viscosity of the oil and it is possible to maintain excellent lubrication performance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a compressor according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the main part (cylinder head portion) of the above first embodiment.

FIG. 3 is a sectional view of a cylinder head portion according to a second embodiment.

FIG. 4 is a sectional view of a cylinder head portion according to a third embodiment.

FIG. 5 is a sectional view of a cylinder head portion according to a fourth embodiment.

FIG. 6 is a sectional view of a cylinder head portion according to a fifth embodiment.

FIG. 7 is a sectional view of a cylinder head portion according to a sixth embodiment.

MODE FOR CARRYING OUT THE INVENTION

Hereinbelow, an embodiment of the present invention will be described in detail.

FIG. 1 is a sectional view of a compressor according to a first embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the main part (cylinder head portion) of the first embodiment.

A basic configuration of a compressor (in particular, a variable displacement compressor) 100 illustrated in FIG. 1 will be described.

The variable displacement compressor 100 is capable of a discharge displacement zero operation and therefore is a clutchless compressor.

The variable displacement compressor 100 includes a cylinder block 101 provided with a plurality of cylinder bores 101 a, a cylinder head 104 provided on one end side of the cylinder block 101 via a valve plate 103, and a front housing 102 provided on the other end side of the cylinder block 101.

A driving shaft 110 is provided across the inside of a crank chamber 140 defined by the cylinder block 101 and the front housing 102, and a swash plate 111 is disposed at a periphery of an intermediate portion in a longitudinal direction of the driving shaft 110. The swash plate 111 is coupled to a rotor 112 fixed to the driving shaft 110 via a link mechanism 120, and the inclination angle thereof is changeable along the driving shaft 110.

The link mechanism 120 includes a first arm 112 a provided to protrude from the rotor 112, a second arm 111 a provided to protrude from the swash plate 111, and a link arm 121, one end of which is rotatably connected to the first arm 112 a via a first connecting pin 122, and the other end of which is rotatably connected to the second arm 111 a via a second connecting pin 123.

A through-hole 111 b of the swash plate 111 is formed to allow the swash plate 111 to incline in a range of a maximum inclination angle and a minimum inclination angle, and a minimum inclination angle restricting portion coming into contact with the driving shaft 110 is formed in the through-hole 111 b. In a case in which the inclination angle of the swash plate when the swash plate 111 is orthogonal to the driving shaft 110 is 0°, the minimum inclination angle restricting portion of the through-hole 111 b is formed such that the swash plate 111 is capable of being inclined up to about 0°. In addition, the maximum inclination angle of the swash plate is restricted when the swash plate 111 comes into contact with the rotor 112.

An inclination angle reducing spring 114 that biases the swash plate 111 until reaching the minimum inclination angle toward the minimum inclination angle is mounted between the rotor 112 and the swash plate 111, and an inclination angle increasing spring 115 that biases the swash plate 111 in a direction in which the inclination angle of the swatch plate is increased is mounted between the swash plate 111 and a spring supporting member 116. Since the biasing force of the inclination angle increasing spring 115 at the minimum inclination angle is set to be greater than the biasing force of the inclination angle reducing spring 114, the swash plate 111 is located at an inclination angle at which the biasing forces of the inclination angle reducing spring 114 and the inclination angle increasing spring 115 are balanced with each other when the driving shaft 110 is not rotating.

One end of the driving shaft 110 extends through the inside of a boss 102 a protruding to the outside of the front housing 102 and extends to the outside, and is coupled to a power transmission device (not illustrated). In addition, a shaft seal device 130 is inserted between the driving shaft 110 and the boss 102 a to cut off the inside and the outside.

An integral structure of the driving shaft 110 and the rotor 112 is supported by bearings 131 and 132 in a radial direction, and is supported by a bearing 133 and a thrust plate 134 in a thrust direction. In addition, a gap between an end face of the driving shaft 110, which faces the thrust plate 134, and the thrust plate 134 is adjusted to a predetermined gap by an adjusting screw 135.

Therefore, the power from an external driving source is transmitted to the power transmission device, and the driving shaft 110 is rotatable in synchronization with the power transmission device.

A piston 136 is disposed within each cylinder bore 101 a, an outer peripheral portion of the swash plate 111 is accommodated in an inner space of an end portion protruding to the crank chamber 140 of the piston 136, and the swash plate 111 is configured to interlock with the piston 136 via a pair of shoes 137. Therefore, the piston 136 is reciprocable within the cylinder bore 101 a by the rotation of the swash plate 111.

A suction chamber 141 is disposed on the inside of the cylinder head 104 in the radial direction, and a discharge chamber 142 is defined so as to annularly surround the outside of the suction chamber 141 in the radial direction. In addition, an oil storage chamber 148 is disposed, as will be described below, at a central portion (a region in which an axis O of the driving shaft 110 extends) of the cylinder head 104, and the suction chamber 141 is defined so as to surround the outside of the oil storage chamber 148 in the radial direction.

The suction chamber 141 communicates with the cylinder bore 101 a via a suction hole 103 a provided in the valve plate 103, and a suction valve (not illustrated) formed in a suction valve forming sheet 152 (FIG. 2). The discharge chamber 142 communicates with the cylinder bore 101 a via a discharge valve (not illustrated) formed in a discharge valve forming sheet 138 (FIG. 2) and a discharge hole 103 b provided in the valve plate 103.

The front housing 102, a center gasket 150, the cylinder block 101, a cylinder gasket 151 (FIG. 2), the suction valve forming sheet 152 (FIG. 2), the valve plate 103, the discharge valve forming sheet 138 (FIG. 2), a head gasket 139 (FIG. 2), and the cylinder head 104 are fastened together by a plurality of through bolts 105 to form a compressor housing.

A suction passage 104 a that allows a suction-side refrigerant circuit of an air-conditioning system and the suction chamber 141 to communicate with each other is formed in the cylinder head 104. The suction passage 104 a has a straight path 104 a 1 that linearly extends from the outside of the cylinder head 104 in the radial direction toward the inside thereof in the radial direction, and a communication passage 104 a 2 that allows the straight path 104 a 1 and the suction chamber 141 to communicate with each other.

Additionally, an upper portion of the cylinder block 101 in FIG. 1 is provided with a muffler, and the muffler is formed by a muffler forming wall 101 b defined by the upper portion of the cylinder block 101 and a lid member 106 being fastened together via a seal member (not illustrated) with bolts. A check valve 200 is disposed in a muffler space 143. The check valve 200 is disposed at a connecting portion between a communication passage 144 formed over the cylinder head 104, the valve plate 103, and the cylinder block 101, and the muffler space 143, operates in response to a pressure difference between the communication passage 144 (upstream side) and the muffler space 143 (downstream side), cuts off the communication passage 144 in a case in which a pressure difference is smaller than a predetermined value, and releases the communication passage 144 in a case in which the pressure difference is greater than the predetermined value. Therefore, the discharge chamber 142 is connected to a discharge-side refrigerant circuit of the air-conditioning system via a discharge passage, which includes the communication passage 144, the check valve 200, the muffler space 143, and a discharge port 106 a.

The cylinder head 104 is further provided with a control valve 300.

The control valve 300 adjusts the opening degree of a pressure supply passage 145, which allows the discharge chamber 142 and the crank chamber 140 to communicate with each other, in response to the pressure of the suction chamber 141 introduced via a pressure introduction passage 147, and an electromagnetic force generated by an electric current that flows into a solenoid, and controls the amount of discharge gas to be introduced into the crank chamber 140. Blowby gas leaking out from a gap between the piston 136 and the cylinder bore 101 a when the piston 136 compresses refrigerant gas, and discharge gas passing through via the control valve 300 flow into the crank chamber 140. The refrigerant within the crank chamber 140 flows into the suction chamber 141 via a pressure release passage 146, which includes a communication passage 101 c, a space 101 d, a throttle 103 c, the oil storage chamber 148, and a communication passage 104 e 1.

The space 101 d is formed between the cylinder block 101 and the valve plate 103 by recessing a central portion of the cylinder block 101. The communication passage 101 c is bored in the cylinder block 101 so as to allow the crank chamber 140 and the space 101 d to communicate with each other.

The throttle 103 c is bored in the valve plate 103 so as to allow the space 101 d on the cylinder block 101 side and the oil storage chamber 148 on the cylinder head 104 side to communicate with each other, and defines a minimum flow passage cross-sectional area of the pressure release passage 146.

The oil storage chamber 148 is a space for forming a portion of the pressure release passage 146 and for separating and storing oil from the refrigerant that flows through the pressure release passage 146. The communication passage 104 e 1 allows the oil storage chamber 148 and the suction chamber 141 to communicate with each other. The oil storage chamber 148 and the communication passage 104 e 1 will be described below in detail.

Therefore, by including the pressure supply passage 145 that allows the discharge chamber 142 and the crank chamber 140 to communicate with each other, the control valve 300 disposed in the pressure supply passage 145, the pressure release passage 146 that allows the crank chamber 140 and the suction chamber 141 to communicate with each other, and the throttle 103 c disposed in the pressure release passage 146, the pressure of the crank chamber 140 is capable of being changed by the control valve 300, and the inclination angle of the swash plate 111, that is, the stroke of the piston 136, is capable of being changed. Specifically, if the pressure of the crank chamber 140 is increased, the inclination angle of the swash plate 111 decreases, and thereby, it is possible to reduce the stroke of the piston 136. Accordingly, the discharge displacement of the variable displacement compressor 100 is capable of being variably controlled.

During the operation of an air-conditioner, that is, in the operating state of the variable displacement compressor 100, the energization amount of the solenoid of the control valve 300 is adjusted by a control device based on an external signal, and the discharge displacement is variably controlled such that the pressure of the suction chamber 141 reaches the predetermined value. Therefore, the control valve 300 is capable of optimally controlling the pressure of the suction chamber 141 according to an external environment.

Additionally, when the air-conditioner is not operated, that is, when the variable displacement compressor 100 is in a non-operating state, by turning off the energization of the solenoid and bringing the pressure supply passage 145 into a fully open state, the pressure of the crank chamber 140 is controlled to the maximum, and the discharge displacement of the variable displacement compressor 100 is controlled to the minimum.

Next, an OCR-reducing structure including the oil storage chamber 148 will be described with reference to FIG. 2.

The cylinder head 104 has an outer peripheral wall 104 b, an end wall (bottom wall) 104 c, the first annular partition wall 104 d that defines the suction chamber 141 and the discharge chamber 142, and a second annular partition wall 104 e disposed on the inside of the first annular partition wall 104 d in the radial direction, and these are integrally formed by aluminum casting. The outer peripheral wall 104 b, the first annular partition wall 104 d, and the second annular partition wall 104 e are concentrically formed about the axis O of the driving shaft 110.

The second annular partition wall 104 e is provided to protrude toward the valve plate 103 from the end wall (bottom wall) 104 c. The height of the second annular partition wall 104 e relative to the outer peripheral wall 104 b and the first annular partition wall 104 d is set such that a tip of the second annular partition wall 104 e presses the valve plate 103 together with a tip of the outer peripheral wall 104 b and a tip of the first annular partition wall 104 d with the head gasket 139 and the discharge valve forming sheet 138 interposed therebetween when the through bolts 105 are fastened to constitute the compressor housing. The second annular partition wall 104 e also has the function as pressing means for holding down the floating of the valve plate 103 when the pressure within a cylinder bore 101 a reaches a high pressure in the compression stroke of the piston 136.

The tip of the second annular partition wall 104 e is brought into contact with the head gasket 139, and a space surrounded by the second annular partition wall 104 e has its opening side blocked by the head gasket 139 to form the oil storage chamber 148.

In addition, this space may be directly blocked by the valve plate 103 by cutting out a portion of the head gasket 139 and the discharge valve forming sheet 138 equivalent to an opening of the space surrounded by the second annular partition wall 104 e.

Therefore, the discharge chamber 142, the suction chamber 141, and the oil storage chamber 148 are formed from the outside of the cylinder head 104 in the radial direction toward the inside (central portion side) thereof in the radial direction by being separated from each other by the first annular partition wall 104 d and the second annular partition wall 104 e that are concentric with each other.

The oil storage chamber 148 is capable of being easily disposed at a central portion of the cylinder head 104 by the second annular partition wall 104 e and the valve plate 103.

A throttle 103 c formed in the valve plate 103 is open in the oil storage chamber 148. Also, the groove-shaped (cut-out) communication passage 104 e 1 that allows the oil storage chamber 148 and the suction chamber 141 to communicate with each other is formed at the tip of the second annular partition wall 104 e that separates the oil storage chamber 148 and the suction chamber 141 from each other.

Therefore, as already described, the crank chamber 140 and the suction chamber 141 communicate with each other via the communication passage 101 c, the space 101 d, the throttle 103 c, the oil storage chamber 148, and the communication passage 104 e 1, and the communication passage 101 c, the space 101 d, the throttle 103 c, the oil storage chamber 148, and the communication passage 104 e 1 form the pressure release passage 146.

Here, the oil storage chamber 148 is disposed on the pressure release passage 146 that allows the crank chamber 140 and the suction chamber 141 to communicate with each other, and the throttle 103 c is disposed on the upstream side (crank chamber 140 side) of the oil storage chamber 148. Therefore, the oil storage chamber 148 becomes a pressure region (a region with the same pressure as that of the suction chamber 141) of the suction chamber 141.

Since the throttle 103 c is formed in the valve plate 103 that defines the oil storage chamber 148, formation also including the adjustment of opening area is easy. However, the throttle 103 c may be formed in the suction valve forming sheet 152, the discharge valve forming sheet 138, or the like. Additionally, the communication passage 104 e 1 may be, for example, a through-hole that passes through the second annular partition wall 104 e instead of the groove.

The oil storage chamber 148 is disposed on the pressure release passage 146 that allows the crank chamber 140 and the suction chamber 141 to communicate with each other as described above, and separates and stores oil from the refrigerant that flows through the pressure release passage 146 depending on a difference in weight (density difference).

The throttle 103 c that is an inlet for the refrigerant to the oil storage chamber 148, and the communication passage 104 e 1 that is an outlet for the refrigerant from the oil storage chamber 148 are formed in a relatively upper portion of the oil storage chamber 148, and the refrigerant flows through the upper portion of the oil storage chamber 148. Since the refrigerant is light and the oil mixed into this refrigerant is heavy, the oil can be separated within the oil storage chamber 148, and the oil can be stored at a bottom portion of the oil storage chamber 148.

Therefore, the space within the oil storage chamber 148 is divided into an upper gas space that forms the pressure release passage 146, and a lower oil storage space in which the separated oil is stored.

Here, in order to secure a sufficient oil storage space, it is desirable that the throttle 103 c and the communication passage 104 e 1 are disposed so as to communicate with an upper space of the oil storage chamber 148 in the gravitational direction.

In addition, if the oil stored in the oil storage chamber 148 rises up to the height of the communication passage 104 e 1, the stored oil flows out of the communication passage 104 e 1 into the suction chamber 141. Therefore, the maximum amount of the oil stored in the oil storage chamber 148 is determined depending on the position of the communication passage 104 e 1. Therefore, it is desirable that the throttle 103 c be disposed above the communication passage 104 e 1 in the gravitational direction.

The opening of the throttle 103 c on the oil storage chamber 148 side faces a bather 104 e 2 formed integrally with the second annular partition wall 104 e, and configured such that a refrigerant stream that flows out of the throttle 103 c into the oil storage chamber 148 collides against the barrier 104 e 2, and oil separation is promoted.

The periphery of the second annular partition wall 104 e becomes the suction chamber 141, the oil stored in the oil storage chamber 148 is cooled by a drawn in refrigerant and is not influenced by the direct heat transfer from the discharge chamber 142.

An appropriate amount of the oil stored in the oil storage chamber 148 flows back to the suction chamber 141 via an oil return passage 149 formed over a lower side of the second annular partition wall 104 e in the gravitational direction, and contributes to the lubrication of the inside of the compressor 100.

The oil return passage 149 includes: a communication hole 138 a that is formed in the discharge valve forming sheet 138, is open to the oil storage chamber 148, and functions as the throttle; a communication hole 138 b that is formed in the discharge valve forming sheet 138 and is open to the suction chamber 141; and a groove 103 d that communicates with the communication hole 138 a on one end side thereof, communicates with the communication hole 138 b on the other end side thereof, and is formed in the valve plate 103.

In addition, either the communication hole 138 b or the groove 103 d may be the throttle. Additionally, a filter may be disposed at an inlet (oil storage chamber 148 side) of the communication hole 138 a. Moreover, the oil return passage 149 may be directly formed in the second annular partition wall 104 e, that is, a groove or a hole may be provided and formed in the second annular partition wall 104 e.

According to the present embodiment, since the second annular partition wall 104 e that defines the oil storage chamber 148 is formed integrally with the cylinder head 104, the oil storage chamber 148 can be easily formed.

Additionally, since the oil storage chamber 148 is defined by the valve plate 103, the pressure release passage 146 can be easily connected to the oil storage chamber 148.

Additionally, the periphery of the oil storage chamber 148 is the suction chamber 141, and is separated from the discharge chamber 142. Therefore, the oil that flows out of the crank chamber 140 into the oil storage chamber 148 and is stored therein is cooled by the drawn in refrigerant. Hence, a decrease in the viscosity of the oil is suppressed and it is possible to maintain excellent lubrication performance.

Additionally, according to the present embodiment, the protruding height of the second annular partition wall 104 e is set such that a protruding-side end portion of the second annular partition wall 104 e presses the valve plate 103 when the cylinder block 101 and the cylinder head 104 are fastened together. Therefore, since the second annular partition wall 104 e has a function as the pressing means for holding down the floating of the valve plate 103, it becomes unnecessary to provide exclusive pressing means.

Additionally, according to the present embodiment, the lower region of the oil storage chamber 148 in the gravitational direction communicates with the suction chamber 141 via the oil return passage 149 with a throttle straddling the second annular partition wall 104 e, and the oil return passage 149 is formed in at least one of the valve plate 103 and interposed members (138, 139) interposed between the valve plate 103 and the cylinder head 104. Therefore, the oil return passage 149 with a throttle can be easily formed.

Next, a second embodiment of the present invention will be described with reference to FIG. 3.

In the embodiment of FIG. 3, the straight path 104 a 1 of the suction passage 104 a is formed to extend, and a constituent wall of an extending portion 140 a 1′ is bulged into the oil storage chamber 148. In other words, the extending portion 104 a 1′ of the straight path 104 a 1 is located behind a wall portion of the oil storage chamber 148.

Moreover, the extending portion 104 a 1′ of the straight path 104 a 1 is made to be directly open to a lower region of the suction chamber 141. Therefore, the suction passage 104 a communicates with the suction chamber 141 at two points, that is, at the communication passage 104 a 2 and the extending portion 104 a 1′.

Particularly, according to the present embodiment, the suction passage 104 a has a straight path (the straight path 104 a 1 and its extending portion 104 a 1′) that linearly extends from the outside of the cylinder head 104 in the radial direction toward the inside thereof in the radial direction, and a constituent wall of the straight path is bulged into the oil storage chamber 148. Therefore, the oil stored in the oil storage chamber 148 can be more easily cooled by the drawn in refrigerant, and the cooling effect of the oil can be improved.

In addition, in the present embodiment, the suction passage 104 a is allowed to communicate with the suction chamber 141 at two points of the communication passage 104 a 2 and the extending portion 104 a 1′. However, the communication passage 104 a 2 may be eliminated, and the suction passage 104 a may be allowed to communicate with the suction chamber 141 only via the extending portion 104 a 1′.

Next, a third embodiment of the present invention will be described with reference to FIG. 4.

In the embodiment of FIG. 4, a tubular space 104 g, which communicates with the straight path 104 a 1 on one end side thereof and communicates with the suction chamber 141 on the other end side thereof via a throttle 104 f, is formed on an extension of the straight path 104 a 1 of the suction passage 104 a, and a constituent wall of the tubular space 104 g is bulged into the oil storage chamber 148.

According to the present embodiment, the refrigerant that is drawn in, which has flowed into the suction passage 104 a from an external refrigerant circuit, can be separated into a refrigerant and oil in the process of passing through the straight path 104 a 1, and the oil separated from the drawn in refrigerant can be stored in the tubular space 104 g separate from the oil storage chamber 148. Additionally, since the constituent wall of the tubular space 104 g is bulged into the oil storage chamber 148, the oil stored in the oil storage chamber 148 can be more easily cooled with the oil separated from the drawn in refrigerant and stored in the tubular space 104 g, and the cooling effect of the oil can be improved. This is because the oil separated from the drawn in refrigerant has a temperature lower than the oil separated from the refrigerant that flows through the pressure release passage 146.

Next, a fourth embodiment of the present invention will be described with reference to FIG. 5.

In the embodiment of FIG. 5, the straight path 104 a 1 of the suction passage 104 a and the oil storage chamber 148 communicate with each other via a connecting path 104 h.

That is, the suction passage 104 a has the straight path 104 a 1 that linearly extends from the outside of the cylinder head 104 in the radial direction toward the inside thereof in the radial direction on the upper side in the gravitational direction, and the upper region of the oil storage chamber 148 in the gravitational direction communicates with the connecting path 104 h that extends from the straight path 104 a 1. In addition, in the present embodiment, the straight path 104 a 1 serving as the suction passage 104 a indicates up to a portion connected to the communication passage 104 a 2.

The connecting path 104 h has a smaller-diameter portion 104 h 1 disposed on the oil storage chamber 148 side, and a larger-diameter portion 104 h 2 disposed on the straight path 104 a 1 side. The smaller-diameter portion 104 h 1 has a smaller diameter than the larger-diameter portion 104 h 2.

The straight path 104 a 1 of the suction passage 104 a and the suction chamber 141 communicate with each other via the communication passage 104 a 2, and communicate with each other via the connecting path 104 h, the upper region of the oil storage chamber 148 in the gravitational direction, and the communication passage 104 e 1. Therefore, the connecting path 104 h, the upper region of the oil storage chamber 148 in the gravitational direction, and the communication passage 104 e 1 form a portion of the suction passage 104 a.

In addition, since the flow passage cross-sectional area of the smaller-diameter portion 104 h 1 is set to be smaller than the minimum flow passage cross-sectional area of the straight path 104 a 1 and the communication passage 104 a 2, a mainstream of the drawn in refrigerant flows through the communication passage 104 a 2.

Therefore, in the oil storage chamber 148, oil is separated due to a difference in weight (density difference) from a refrigerant gas flow that flows toward the suction chamber 141 from the crank chamber 140, the separated oil is stored in the lower region of the oil storage chamber 148, and the refrigerant gas reaches the suction chamber 141 via the communication passage 104 e 1.

Additionally, although the refrigerant that circulates through the external refrigerant circuit flows into the suction chamber 141 from the suction passage 104 a, the oil that circulates with the drawn in refrigerant also flows into the suction chamber. Since the oil storage chamber 148 is on the extension of the straight path 104 a 1, the oil separated from the drawn in refrigerant due to the difference in weight is collected in the larger-diameter portion 104 h 2 of the connecting path 104 h, and flows into the oil storage chamber 148 via the smaller-diameter portion 104 h 1. Since the refrigerant flowing into the oil storage chamber 148 is suppressed by the smaller-diameter portion 104 h 1, it is possible to prevent the stored oil from being stirred.

In the present embodiment, the oil storage chamber 148 can not only separate and store oil from the refrigerant that flows into the suction chamber 141 from the crank chamber 140, but can also store the oil separated from the refrigerant that flows through the suction passage 104 a.

Additionally, since the connecting path 104 h can be formed integrally with the straight path 104 a 1, there is little effect on cost.

According to the present embodiment, the suction passage 104 a has the straight path 104 a 1 that linearly extends from the outside of the cylinder head 104 in the radial direction toward the inside thereof in the radial direction, the upper region of the oil storage chamber 148 in the gravitational direction communicates with the connecting path 104 h that extends from the straight path 104 a 1, and the connecting path 104 h has the smaller-diameter portion 104 h 1 having a smaller diameter than the straight path 104 a 1. Therefore, the oil separated from the drawn in refrigerant can also be stored in the oil storage chamber 148. Since the connecting path 104 h has the smaller-diameter portion 104 h 1, it is possible to prevent the inflow of the drawn in refrigerant into the oil storage chamber 148, and it is possible to prevent the stored oil from being stiffed.

Additionally, according to the present embodiment, the connecting path 104 h has the larger-diameter portion 104 h 2 that is disposed closer to the straight path 104 a 1 than the smaller-diameter portion 104 h 1 and has a larger diameter than the smaller-diameter portion 104 h 1. Therefore, since the larger-diameter portion 104 h 2 becomes an oil storage space, the oil separated from the drawn in refrigerant due to the difference in weight can be effectively guided to the oil storage chamber 148.

Additionally, according to the present embodiment, the suction passage 104 a has a first passage (communication passage 104 a 2) that directly reaches the suction chamber 141 from the straight path 104 a 1, and a second passage (communication passage 104 e 1) that reaches the suction chamber 141 via the connecting path 104 h and the upper region of the oil storage chamber 148 in the gravitational direction from the straight path 104 a 1, and the minimum flow passage cross-sectional area (the cross-sectional area of the smaller-diameter portion 104 h 1) of the second passage is set to be smaller than the minimum flow passage cross-sectional area of the first passage. Therefore, the oil separated from the drawn in refrigerant can easily flow into the oil storage chamber 148 from the connecting path 104 h.

Next, a fifth embodiment of the present invention will be described with reference to FIG. 6.

In the embodiment of FIG. 6, the communication passage 104 e 1 (refer to FIGS. 1 to 5) that allows the oil storage chamber 148 and the suction chamber 141 to directly communicate with each other is eliminated. Also, the straight path 104 a 1 of the suction passage 104 a and the oil storage chamber 148 communicate with each other via the connecting path 104 h, and the connecting path 104 h is configured to form a portion of the pressure release passage 146.

That is, the suction passage 104 a has the straight path 104 a 1 that linearly extends from the outside of the cylinder head 104 in the radial direction toward the inside thereof in the radial direction on the upper side in the gravitational direction, and the upper region of the oil storage chamber 148 in the gravitational direction communicates with the connecting path 104 h that extends from the straight path 104 a 1. In addition, in the present embodiment, the straight path 104 a 1 serving as the suction passage 104 a indicates up to a portion connected to the communication passage 104 a 2.

The connecting path 104 h also serves as a portion of the pressure release passage 146 that allows the oil storage chamber 148 and the suction chamber 141 to communicate with each other, and the flow passage cross-sectional area of the connecting path 104 h is set to be greater than the flow passage cross-sectional area of the throttle 103 c.

Therefore, in the oil storage chamber 148, oil is separated due to a difference in weight (density difference) from a refrigerant gas flow that flows toward the suction chamber 141 from the crank chamber 140, the separated oil is stored in the lower region of the oil storage chamber 148, and the refrigerant gas reaches the suction chamber 141 via the connecting path 104 h, the straight path 104 a 1, and the communication passage 104 a 2.

Additionally, although the refrigerant that circulates through the external refrigerant circuit flows into the suction chamber 141 from the suction passage 104 a, the oil that circulates with the drawn in refrigerant also flows into the suction chamber. Since the oil storage chamber 148 is on the extension of the straight path 104 a 1, the oil separated from the drawn in refrigerant due to the difference in weight flows into the oil storage chamber 148 from the connecting path 104 h and is stored therein.

In the present embodiment, there is no need for providing the communication passage 104 e 1 (refer to FIGS. 1 to 5) in the second annular partition wall 104 e, and it is possible to simplify a passage configuration.

According to the present embodiment, the suction passage 104 a has the straight path 104 a 1 that linearly extends from the outside of the cylinder head 104 in the radial direction toward the inside thereof in the radial direction, the upper region of the oil storage chamber 148 in the gravitational direction communicates with the connecting path 104 h that extends from the straight path 104 a 1, and the connecting path 104 h forms a portion of the pressure release passage 146. Therefore, since the connecting path 104 h serves as the pressure release passage 146, it is possible to simplify passage formation.

Next, a sixth embodiment of the present invention will be described with reference to FIG. 7.

In the embodiment of FIG. 7, the straight path 104 a 1, the upper region of the oil storage chamber 148 in the gravitational direction, and the communication passage 104 e 1 are configured so as to become the suction passage 104 a.

Additionally, although the refrigerant that circulates through the external refrigerant circuit flows into the oil storage chamber 148 from the straight path 104 a 1, the oil that circulates with the drawn in refrigerant also flows into the oil storage chamber. The opening of the straight path 104 a 1 on the oil storage chamber 148 side faces a barrier 104 i that extends from the end wall (bottom wall) 104 c of the cylinder head 104. Therefore, the drawn in refrigerant is collided against the barrier 104 i to promote the separation of the oil, the separated oil is stored in the lower region of the oil storage chamber 148, and the refrigerant gas flows into the suction chamber 141 from the communication passage 104 e 1. Therefore, the same effects as those of the aforementioned embodiments can be obtained.

In addition, it goes without saying that the illustrated embodiments merely illustrate the present invention, and the present invention includes various improvements and modifications made by those skilled in the art within the scope of the claims in addition to those directly illustrated in the described embodiments.

For example, in the above embodiments, the oil storage chamber 148 is the pressure region (the region having the same pressure as that of the suction chamber 141) of the suction chamber 141 by disposing the throttle 103 c of the pressure release passage 146 upstream of the oil storage chamber 148. However, the oil storage chamber 148 may be the pressure region (the region having the same pressure as that of the crank chamber 140) of the crank chamber 140 by disposing the throttle of the pressure release passage 146 downstream of the oil storage chamber 148, and the oil stored in the oil storage chamber 148 may be returned to the crank chamber 140 via the throttle.

Additionally, in the above embodiments, the present invention is applied to the variable displacement compressor. However, the present invention is applicable to all reciprocating compressors including a fixed-displacement compressor.

REFERENCE SYMBOL LIST

-   100 variable displacement compressor -   101 cylinder block -   101 a cylinder bore -   101 b muffler forming wall -   101 c communication passage -   101 d space -   102 front housing -   102 a boss -   103 valve plate -   103 a suction hole -   103 b discharge hole -   103 c throttle -   103 d groove -   104 cylinder head -   104 a suction passage -   104 a 1 straight path -   104 a 2 communication passage -   104 a 1′ extending portion of straight path -   104 b outer peripheral wall -   104 c end wall -   104 d first annular partition wall -   104 e second annular partition wall -   104 e 1 communication passage -   104 e 2 barrier -   104 f throttle -   104 g tubular space -   104 h connecting path -   104 h 1 smaller-diameter portion -   104 h 2 larger-diameter portion -   104 i barrier -   105 through bolt -   106 lid member -   106 a discharge port -   110 driving shaft -   111 swash plate -   111 a second arm -   111 b through-hole -   112 rotor -   112 a first arm -   114 inclination angle reducing spring -   115 inclination angle increasing spring -   116 spring supporting member -   120 link mechanism -   121 link arm -   122 first connecting pin -   123 second connecting pin -   130 shaft seal device -   131, 132 bearing -   133 bearing -   134 thrust plate -   135 adjusting screw -   136 piston -   137 shoe -   138 discharge valve forming sheet -   138 a, 138 b communication hole -   139 head gasket -   140 crank chamber -   141 suction chamber -   142 discharge chamber -   143 muffler space -   144 communication passage -   145 pressure supply passage -   146 pressure release passage -   147 pressure introduction passage -   148 oil storage chamber -   149 oil return passage -   150 center gasket -   151 cylinder gasket -   152 suction valve forming sheet -   200 check valve -   300 control valve 

1. A compressor that includes a cylinder block that has a plurality of cylinder bores and has a piston mounted on each of the cylinder bores, and a cylinder head that is disposed on one end side of the cylinder block via a valve plate and defines a suction chamber on the inside thereof in a radial direction and a discharge chamber on the outside thereof in the radial direction, and in which the piston is reciprocated by a swash plate that rotates in synchronization with a driving shaft to draw a refrigerant into the cylinder bore from the suction chamber and compress the refrigerant within the cylinder bore to discharge the refrigerant to the discharge chamber, the compressor comprising: a pressure release passage that allows a crank chamber, in which the swash plate is disposed, and the suction chamber to communicate with each other; and an oil storage chamber that forms a portion of the pressure release passage and separates oil from the refrigerant flowing through the pressure release passage to store the oil, wherein the oil storage chamber is defined by an annular partition wall and the valve plate, wherein the annular partition wall is formed integrally with the cylinder head, is provided to protrude toward the valve plate from a bottom wall of the cylinder head, and has an outer peripheral portion surrounded by the suction chamber.
 2. The compressor according to claim 1, wherein a protruding height of the annular partition wall is set such that a protruding-side end portion of the annular partition wall presses the valve plate when the cylinder block and the cylinder head are fastened to each other.
 3. The compressor according to claim 2, wherein a lower region of the oil storage chamber in a gravitational direction communicates with the suction chamber via an oil return passage with a throttle straddling the annular partition wall, and wherein the oil return passage is formed in at least one of the valve plate and an interposed member interposed between the valve plate and the cylinder head.
 4. The compressor according to claim 1, wherein a suction passage that allows an external refrigerant circuit and the suction chamber to communicate with each other is formed in the cylinder head, and wherein the suction passage has a straight path that linearly extends from the outside of the cylinder head in the radial direction toward the inside thereof in the radial direction, and a constituent wall of the straight path is bulged into the oil storage chamber.
 5. The compressor according to claim 1, wherein a suction passage that allows an external refrigerant circuit and the suction chamber to communicate with each other is formed in the cylinder head, wherein the suction passage has a straight path that linearly extends from the outside of the cylinder head in the radial direction toward the inside thereof in the radial direction, and wherein a tubular space, which communicates with the straight path on one end side thereof and communicates with the suction chamber on the other end side thereof via a throttle, is formed on an extension of the straight path, and a constituent wall of the tubular space is bulged into the oil storage chamber.
 6. The compressor according to claim 1, wherein the oil storage chamber becomes a pressure region of the suction chamber, wherein a suction passage that allows an external refrigerant circuit and the suction chamber to communicate with each other is formed in the cylinder head, wherein the suction passage has a straight path that linearly extends from the outside of the cylinder head in the radial direction toward the inside thereof in the radial direction, wherein an upper region of the oil storage chamber in a gravitational direction communicates with a connecting path that extends from the straight path, and wherein the connecting path has a smaller-diameter portion having a smaller diameter than the straight path.
 7. The compressor according to claim 6, wherein the connecting path has the smaller-diameter portion, and a larger-diameter portion that is disposed closer to the straight path than the smaller-diameter portion and has a larger diameter than the smaller-diameter portion.
 8. The compressor according to claim 6, wherein the suction passage has a first passage that directly reaches the suction chamber from the straight path, and a second passage that reaches the suction chamber via the connecting path and the upper region of the oil storage chamber in the gravitational direction from the straight path, and a minimum flow passage cross-sectional area of the second passage is set to be smaller than a minimum flow passage cross-sectional area of the first passage.
 9. The compressor according to claim 1, wherein the oil storage chamber becomes a pressure region of the suction chamber, wherein a suction passage that allows an external refrigerant circuit and the suction chamber to communicate with each other is formed in the cylinder head, wherein the suction passage has a straight path that linearly extends from the outside of the cylinder head in the radial direction toward the inside thereof in the radial direction, wherein an upper region of the oil storage chamber in a gravitational direction communicates with a connecting path that extends from the straight path, and wherein the connecting path forms a portion of the pressure release passage.
 10. The compressor according to claim 1, further comprising: a pressure supply passage that allows the discharge chamber and the crank chamber to communicate with each other; a control valve disposed in the pressure supply passage; and a throttle disposed upstream of the oil storage chamber of the pressure release passage, wherein the swash plate is configured such that an inclination angle thereof is changeable, and when the pressure of the crank chamber increases, the inclination angle decreases and thereby the stroke of the piston decreases. 